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Publication numberUS3896206 A
Publication typeGrant
Publication dateJul 22, 1975
Filing dateJun 25, 1973
Priority dateJun 25, 1973
Publication numberUS 3896206 A, US 3896206A, US-A-3896206, US3896206 A, US3896206A
InventorsBeaver Guy Daniel, Martin Donald Theodore, Young Robert Cleland
Original AssigneeBabcock & Wilcox Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Method for forming and curing a fiber reinforced hollow epoxy shaft
US 3896206 A
Abstract
A method of forming a fiber reinforced composite tapered shaft formed upon a tapered mandrel, and the shaft with the mandrel therein is molded in a mold with the mandrel longitudinally forced into the shaft to radially compress the shaft material under heating conditions and to thereby form a finished composite tapered shaft.
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Description  (OCR text may contain errors)

United States Patent Beaver et al. July 22, 1975 [54] METHOD FOR FORMING AND CURING A 2,710,026 6/1955 Stewart .1 264/137 X FIBER REINFORCED HOLLOW EPOXY 2942197 6/1960 Mlchalkow 3,655,863 4/1972 Andersen .1 264/325 X SHAFT [75} Inventors: Guy Daniel Beaver, Wadsworth;

Robert Cleland Young, Louisville; Primary Examiner-Richard R. Kucia Donald Theodore Martin, Alliance, Attorney, Agent, or Firm-J. M. Maguire', E. A all of Ohio Mosley {73] Assignee: The Babeock & Wilcox Company, New York, NY.

[22] Filed: June 25, 1973 [57] ABSTRACT 21 A l, N 373,206 l 1 PP 0 A method of forming a fiber reinforced composite tapered shaft formed upon a tapered mandrel, and the H /134; 4/137; shaft with the mandrel therein is molded in a mold 264/325 with the mandrel longitudinally forced into the shaft [51] Int. Cl 529d 9/ E to radially compress the shaft material under heating Field of Search conditions and to thereby form a finished composite 264/137, 258, 294, 296; 156/165 tapered h ft,

[56] References cued 6 Claims, 2 Drawing Figures UNITED STATES PATENTS Blount .1 264/325 X METHOD FOR FORMING AND CURING A FIBER REINFORCED HOLLOW EPOXY SHAFT The present invention relative to a method of curing a fiber reinforced plastic shaft, and more particularly to a mold for such a shaft and a method of compressing materials of the shaft in the mold prior to or during thermal treatment of the plastic.

In the manufacture of fiber reinforced plastic articles curing of the plastic becomes necessary. The materials are received in a compounded form where the fiber and the plastic matrix which may be a polymer or a resin, are laid up in a preferred form prior to curing of the finished article. Ordinarily, the material containing the fiber and its matrix is known as a molding compound, and where fibers are oriented in a preferred arrangement referred to as a prepreg. After the materials are laid up in the general form desired for the finished product they must be compacted to remove air and to fill any voids, prior to or during the application of heat. The application of heat and pressure is ordinarily used either separately or simultaneously to lower the viscosity of the plastic thereby helping remove the air, and finally curing the shape to its final configuration.

There are many methods for compacting the fiber re inforced plastic matrix. The most common methods utilize contact pressure produced by hand rollers or paddles. Sometimes pressure is applied by utilizing vacuum under a film. Autoclave processes are used which may combine the use of a vacuum with subsequent high pressure, such as for example 100 psi (pounds per square inch), admitted to force compaction of the fiber reinforced plastic material.

In accordance with the present invention the general principle of a wedge is used to compact a hollow tubu lar article made up of fiber reinforced plastic materials. More specifically a hollow tubular article is formed by wrapping layers of fiber preimpregnated with resin on a tapered mandrel. This assembly is placed in a mold cavity and the mandrel is forced into the mold to compact the fiber resin materials. It will be appreciated that the size of the tubular product so treated may be measured in inches or feet insofar as length is concerned and the thickness of the hollow article so compacted may be as little as one one-hundreth of an inch or several inches. In the drawings:

FIG. 1 shows in section, an isometric view ofa hollow tubular shaft positioned in a mold in accordance with the invention;

FIG. 2 is a section view taken on line 22 of FIG. I;

ln the illustrated embodiment of the invention, a fiber reinforced plastic shaft is initially formed on a tapered mandrel ll of circular cross section. The hollow tapered shaft 10 is installed in a two part steel mold 12 having a cavity therein. The innermost layer 13 of fiber reinforced plastic is constructed with the fibers 14 therein extending an appreciable distance beyond the nominal larger end 15 of the hollow shaft. These fibers extend around an annular rounded nose section 16 formed on the mold l2 and are locked in position by a clamp member 17 so as to anchor the longitudinal position of the innermost fiber reinforced layer 13 during the period of time that the fibers in the shaft are radially expanded to compress the hollow shaft 10, as hereinafter described.

A film or layer such as silicone rubber or fluorocarbon in either solid or liquid form one one-thousandth to one-tenth inch thick is positioned between the exterior surface of the mandrel 11 and the innermost layer 13 of the fiber reinforced resin of the shaft 10 to at least act as a partial lubricating and/or release agent. Thus when the mandrel 11 is moved longitudinally of the mold 12 the radial expansion of the shaft 10 will be possible. The use of the film combined with longitudinal fixing of the position of the inner layer 13 by the clamp 17 will permit compacting of the fiber reinforced plastic of the shaft without deleterious effects on the compressed and cured shaft.

The radial compression of the shaft 10 by longitudinal movement of the mandrel 11, (to the right in FIG. I) may be accomplished by any suitable mechanism, such as a screw, jack or a pneumatic or hydraulic cylin der. As shown in FIG. 1, a cylinder 20 with a piston 21 therein having a piston rod 22 attached thereto. The rod 22 is detachably connected with the large end 23 of the mandrel 11, and with the cylinder fixed in its relationship to the mold 12, application of fluid pressure to the cylinder through conventional piping connections (not shown) will cause movement of the mandrel.

During the application of heat and compressive forces to the shaft 10 the viscosity of the plastic will be initially decreased, and it becomes necessary to seal the ends of the shaft 10 to prevent loss of plastic. Typicals seal rings 25 are shown at the opposite ends of the mold I2 cavity for this purpose.

In the embodiment of the invention shown the shaft 10 is formed on a tapered mandrel, as for example in the manner disclosed and claimed in a companion application by Kristina Lauraitis, Ser. No. 379,686, filed July 16, 1973. In this example the shaft is formed of multiple layers of organic fiber reinforced epoxy on a mandrel which uniformly tapers from about 0.5 inch at one end to about 0.1 inch at the other end in a length of approximately 45 inches. The exterior dimensions of the shaft so formed may vary within some fairly close limits depending upon the desired characteristics of the composite shaft, but in general terms the thickness of the wall will be about 0.1 inches and need not be of uniform thickness throughout its length.

The shaft formed as described, with its tapered mandrel, is positioned in the mold 12 where the cavity of the mold will have a configuration corresponding to the desired finished or cured shape. The hollow shaft, with its mandrel, might be considered in a raw state or condition, in so far as the curing procedure is concerned, when placed in the mold 12. The fibers 14 extending from the inner layer 15 are clamped to the mold over the annulus 16 by the clamp member 17 and the two portions of the mold are closed in a secured position. The rod 22 is then connected with the mandrel and the assembly is ready for final treatment by the application of compressive forces to and curing of the raw materials of the hollow multilayer fiber reinforced shaft.

To cure the fiber reinforced resin of the example given, a temperature of 250 to 350F is required. for a period of time at temperature of between l0 and minutes. Other plastic and thicker shapes may require other temperatures and periods of time, as well known in the art. The arrangements for heating the mold and the shaft therein is also well known in the art, and may take the form of external heating of the entire mold from an external source, or internal heating by passing hot fluids through passageways formed in the mold.

Electrical heating has also been utilized for mold heating purposes.

In the procedure of the present invention, pressure is applied to the mandrel 11 by the piston 21 while the tapered shaft is being heated. Ordinarily the pressure is increased as the shaft and mold temperature increases with a maximum desired pressure attained when the temperature reaches 200 to 350F, depending upon the particular resin system.

The pressure applied is determined by the amount of radial displacement of the hollow shaft desired or required to attain the finished product. This in turn can be measured by the amount of longitudinal movement of the mandrel necessary to accomplish the desired result, or alternately movement may be regulated by the amount of pressure applied on the piston.

When sufficient displacement has been attained to achieve the desired compression of the hollow shaft, and the curing temperature has been maintained for a sufficient length of time the shaft is allowed to cool. Such cooling may be accomplished within the mold, i.e. the shaft is retained in the mold, with the mold cooled by natural heat radiation to the atmosphere. Alternately the mold 12 may be opened and the shaft re moved for either forced or slow cooling depending upon the particular resin used in making the shaft. When the shaft has cooled, the mandrel will be driven from the shaft and the cured shaft is then ready for trimming to the precise length required. The surface can be finished with various coatings to produce the color, luster, or environmental protention required before assembly with the head of a golf club and a grip at the larger end.

It will be noted the mold cavity surface may be smoothly tapered or provided with a stepped taper, as desired. Furthermore, as hereinbefore pointed out the dimensions of the finished product may vary between wide limits, depending upon the end use of the tapered hollow product.

What is claimed is:

1. In the method of curing a tapered multilayered fiber reinforced plastic shaft having a tapered mandrel therein wherein the angle of mandrel taper is less than one degree, the intersurface between the exterior of the mandrel and the innermost layer of fiber reinforced plastic having a film of lubricant therebetween, the innermost layer of fiber reinforced plastic having the fibers therein extended beyond the other layers at the end of the shaft adjacent the larger end of the mandrel, the improved method comprising placing the shaft and mandrel in a mold, fixing the extended ends of the fibers of the innermost layer to the mold, heating the mold and the shaft therein to a selected temperature, forcing the tapered mandrel longitudinally into the shaft to exert an outward pressure on the shaft, controlling the longitudinal movement of the mandrel to determine the radial pressure exerted on the shaft, removing the mandrel and shaft from the mold, and removing the mandrel from the shaft.

2. In the method of claim 1 including maintaining the temperature of the shaft in the mold a selected period of time, and discontinuing heating of the mold to permit cooling thereof.

3. In the method of claim 2 wherein the shaft and mandrel are removed from the mold immediately after mold heating has been discontinued.

4. In the method of claim 1 wherein the shaft is heated to a temperature above 200F before forcing the mandrel into the tapered shaft.

5. In the method of claim 1 wherein the shaft is heated to a maximum temperature of approximately 305F.

6. In the method of claim 1 wherein layer of silicone rubber is applied to the mandrel before the layers of fiber reinforced polymer is placed thereon.

UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT N0. 3,896,206 DATED July 2 1975 |NVENTOR(S) 1 Guy D. Beaver et al It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

The address of inventor, Robert Cleland. Young should read --Alliance--.

The address of inventor, Donald Theodore Martin should read --Louisville-.

Column line 3 T "305 1 should read--35O F--.

Signed and Scaled this RUTH C. MASON C. IAISIIALL DANN Alluring Officer (omminflmn of hmm and Trademarks

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2202042 *Jan 13, 1938May 28, 1940Clinton W BlountMethod of manufacturing hollow objects
US2710026 *Jul 19, 1950Jun 7, 1955Continental Diamond Fibre CoMolded tapered tubes and method of making same
US2942297 *Sep 27, 1956Jun 28, 1960Union Carbide CorpApparatus for shaping thermoplastic fabrics
US3655863 *Jan 9, 1970Apr 11, 1972Monsanto CoMethod of making a contoured composite product
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4058584 *Apr 1, 1975Nov 15, 1977Enrique Ubach AloyMethod for manufacturing luminous hollow bodies for signs or the like
US4160639 *Jun 6, 1978Jul 10, 1979Toyoji UmedaManufacturing process and straightening jig for hollow tapered rods
US4289168 *Sep 17, 1979Sep 15, 1981Societe Nationale Industrielle Et AerospatialeMethod for making pipe of fabric impregnated with resin
US4683099 *Feb 20, 1986Jul 28, 1987Rolls-Royce PlcMoulding of composite materials
US4780262 *Feb 17, 1987Oct 25, 1988The Boeing CompanyMethod for making composite structures
US4849152 *Aug 9, 1983Jul 18, 1989The Boeing CompanyCone control method for fabricating composite shafts
US4935185 *Oct 24, 1988Jun 19, 1990Diversified Products CorporationMethod of making a fibre-reinforced molded racquet frame
US5143669 *Jun 18, 1990Sep 1, 1992Diversified Products CorporationFiber-reinforced molded racquet frame
US5236538 *Sep 29, 1992Aug 17, 1993The Boeing CompanyCone control tool for manufacturing composite shafts
US5244622 *Sep 30, 1992Sep 14, 1993The Boeing CompanyCone control method for fabricating composite shafts
US5262118 *Mar 20, 1992Nov 16, 1993Yamaha CorporationMethod for producing a hollow FRP article
US5332606 *Oct 18, 1993Jul 26, 1994Edo Sports, Inc.Filament-wound tubular element manufacturing method and product
US5409651 *Oct 6, 1993Apr 25, 1995Atkins & Pearce, Inc.Method of forming tubular parts
US5484498 *Nov 18, 1992Jan 16, 1996Hogarth; Harold P.Molded article and method and apparatus for making same
US5534203 *Feb 9, 1994Jul 9, 1996Radius Engineering, Inc.Composite pole manufacturing process for varying non-circular cross-sections and curved center lines
US5567374 *Nov 17, 1994Oct 22, 1996Applied Research Of Australia, Pty. Ltd.Polymeric moldings reinforced with tows of fibers
US5989481 *Jun 18, 1996Nov 23, 1999You; Daniel H.Golf club shaft manufacturing process
US6148865 *Dec 2, 1996Nov 21, 2000A & P Technology, Inc.Braided sleeve, tubular article and method of manufacturing the tubular article
US6250193Oct 2, 1997Jun 26, 2001A & P Technology, Inc.Braided structure with elastic bias strands
US6824636Jul 19, 2002Nov 30, 2004Radius Engineering, Inc.Method of manufacturing a composite golf club head
US7575706 *Sep 24, 2004Aug 18, 2009Column & Post, Inc.Mold and molding process
US7811495 *Oct 12, 2010University Of Maine System Board Of TrusteesComposite construction members and method of making
US8522486 *Sep 27, 2010Sep 3, 2013University Of Maine System Board Of TrusteesComposite structural member
US8591788Sep 27, 2010Nov 26, 2013University Of Maine System Board Of TrusteesMethod of forming a composite structural member
US8850750Jan 26, 2005Oct 7, 2014University Of Maine System Board Of TrusteesRapidly-deployable lightweight load resisting arch system
US8935888 *Sep 3, 2013Jan 20, 2015University Of Maine System Board Of TrusteesComposite structural member
US9120250 *Oct 6, 2011Sep 1, 2015Gkn Aerospace Services LimitedStructure comprising an annular housing made of composite material
US9273631 *Mar 1, 2011Mar 1, 2016Gkn Aerospace Services LimitedSeamless acoustic liner
US20020190439 *Jul 19, 2002Dec 19, 2002Nelson Ronald H.Method of manufacturing a composite golf club head
US20050062201 *Sep 24, 2004Mar 24, 2005Koren Robert DouglasMold and molding process
US20060174549 *Jan 26, 2005Aug 10, 2006Dagher Habib JRapidly-deployable lightweight load resisting arch system
US20070175577 *Dec 19, 2006Aug 2, 2007Dagher Habib JComposite construction members and method of making
US20090039566 *Jul 21, 2008Feb 12, 2009Rodman William LComposite structures and methods of making same
US20110011008 *Sep 27, 2010Jan 20, 2011University Of Maine System Board Of TrusteesComposite construction members and method of making
US20110012282 *Sep 27, 2010Jan 20, 2011University Of Maine System Board Of TrusteesComposite construction members and method of making
US20130075193 *Mar 1, 2011Mar 28, 2013Armando VavalleSeamless acoustic liner
US20130192749 *Oct 6, 2011Aug 1, 2013Gary WilesStructure comprising an annular housing made of composite material
US20140069024 *Sep 3, 2013Mar 13, 2014University Of Maine System Board Of TrusteesComposite Structural Member
US20140367920 *Jun 12, 2014Dec 18, 2014Composite IndustriePiece of abradable material for the manufacture of a segment of an abradable ring seal for a turbomachine, and process for the manufacture of such a piece
EP0010024A1 *Sep 19, 1979Apr 16, 1980AEROSPATIALE Société Nationale IndustrielleProcess for manufacturing conduits of resin-impregnated fabric and conduits so obtained
EP0203210A1 *May 25, 1985Dec 3, 1986The Boeing CompanyCone control method and tool for fabricating composite shafts
WO2014147224A3 *Mar 21, 2014Jan 22, 2015Supertex Composites GmbhConnection device for introducing matrix material into a cavity containing reinforcement fibres in a semifinished structural member and supply system comprising such a connection device and method for supplying matrix material
Classifications
U.S. Classification264/258, 264/325, 264/134, 264/137
International ClassificationB29C70/46, B29C70/04
Cooperative ClassificationB29C70/462, B29C2037/92
European ClassificationB29C70/46A
Legal Events
DateCodeEventDescription
Dec 11, 1981AS02Assignment of assignor's interest
Owner name: BABCOCK & WILCOX COMPANY THE
Owner name: DRESSER INDUSTRIES, INC.
Effective date: 19811119
Owner name: THE DRESSER BLDG., 1505 ELM ST., DALLAS, TX. A COR
Dec 11, 1981ASAssignment
Owner name: DRESSER INDUSTRIES, INC.; THE DRESSER BLDG., 1505
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:BABCOCK & WILCOX COMPANY THE;REEL/FRAME:003934/0072
Effective date: 19811119